Trying to hide it in 'Other products' reveals Cook's insecurity and complete lack of confidence in this device.
The opposite. It's more likely Cook's secure knowledge that many other watch makers consider the Apple Watch their biggest completion for customers, and are looking for every tiny bit of competitive information they can get to try and halt Apple's momentum.
Plus, given that the sales were nearly 100% constrained by manufacturing output, it tells the competition exactly how fast Apple can ramp up production of new devices.